New anesthetic circuit system with anesthetic mask for rodents. A closed anesthetic circuit for controlled anesthesia in mice and rats. Masks in different sizes for mice and rats. A wear-free membrane seals flexibly and completely, so that no anesthetic gas gets into the environment of the user and the anesthesia can thus be ideally controlled. The membrane is thermally stable and dimensionally stable and can be disinfected without any problems. The aluminum mask base offers a stable hold in individual applications and on heating plates and can optionally also be used with the OR work surface (RAC-Pro Set).